Optical devices, such as cameras or integrated camera optics, are nowadays integrated in a large percentage of any electronic devices manufactured, including mobile phones, computers, etc. It is increasingly important that such cameras can be manufactured economically, for example in a parallel process, and that they have as few parts as possible that are mechanically complicated, difficult to manufacture or delicate to handle. Especially for mobile phone applications but also for other applications, there is moreover an increasing demand for cameras that are thin, i.e. the extension in direction of the optical axis (z extension) is small. Nevertheless, there is also an increasing demand on the resolution that should be achieved by such integrated cameras.
Digital signal processing has made cameras with no movable parts increasingly effective. Functions such as focusing that previously had to be carried out mechanically can be carried out by according software in accordance with a concept that has become known under the name “computational photography”. One concept that has become known is the so-called ‘plenoptic camera’ that uses data on the direction from which radiation impinges to calculate 3D information of an image taken. There is also software available that can calculate a high resolution image from a plurality of low resolution images taken from a same viewpoint at the same time. An example of an according teaching can be found in EP 1 357 514 and the references cited therein. A further example of an according teaching that relates to a camera array is disclosed in WO 2009/151903.
One problem that arises often in compact cameras is the handling of stray light. The thinner and smaller the camera is, the more difficult this may become, among other things because for thin cameras there may be stray light paths to the actual sensor also for light impinging from flat angles